Almost everywhere I look, especially here on WiiHacks, I see people saying the Wii U can NOT use a USB powered HDD because the Wii U doesn't supply enough power. I also see claims that you can use a Y cable to rectify this but that is not a guarantee. Now, while browsing YouTube for Wii U reviews and recommendations, I see video of a few people who have USB powered HDDs and they work...I'm now confused. Nearest I can guess is that some drives take less power than others which leads to me ask, how can I determine how much power the WiiU USB ports output and how much power a HDD requires to run? I only ask this cause if I can save myself from spending another $50+ on a HDD I don't need I would love that.

The USB ports on the Wii U supply appx 500mA of power each. You will have to look up the specs on your drive to find out how much power it takes. Now, take my HDD for example. It is a WD My Passport 320. Specs say it takes 1A, (1000mA). However, even with a Y cable it still didn't have enough power to spin up. My solution was to rewire the power wires on the Y cable with an old 1A cell phone USB charger (super cheap on ebay). It immediately fired up and I haven't had a problem since. So the lesson from this is that you can try the Y cable. It might work depending on your drive's power needs. If it doesn't work, you are left with either the route I took, or to go get a different drive.